“We’ve been together for so long,” Kate – who stopped by Access Hollywood Live on Thursday to talk about her charity work with Operation Smile – told Kit Hoover and Billy Bush. “I’m gonna miss the cast and crew so much. We’re making the most of every second.

“It’s been a great ride, but I’m looking forward to whatever’s next,” she added.

And the 45–year-old actress is already working on “whatever’s next,” starting with a project she and her comedy writer boyfriend created.

“I sold a project, a half-hour sitcom, for NBC. But I’m producing on that,” she said, adding that she will not appear on the show. “It’s loosely based on [my life]. It’s me, but not me.”

The show was partially inspired by experiences with blending her life with that of her beau’s (who has children).

“It’s loosely based on our experience — you know, he’s got kids,” she said. “[It’s about] what it’s like with me coming in and kind of working together with the kids and the whole crazy life… it’s been really amazing.”

Watch Kate on the final season of “Private Practice,” Tuesdays at 10/9c on ABC.